The major goal of the project is to determine the contamination level of endocrine disrupting compounds (EDCs) in the border area and to investigate the associated estrogenic effects using human-based assays. In previous work, we have identified the presence of nonylphenol (NP) in wastewater collected from El Paso. Our result shows that nonylphenol was present in both untreated and treated wastewater at 213 and 21 parts per billion (ppb) respectively. Both concentrations exceed the 6.6 ppb Criterion Continuous Concentration (CCC) in surface water set by USEPA for nonylphenol. Based on the finding, this proposed study is aimed to conduct a combination of simultaneous chemical and effect-oriented research. Specifically, the objectives of this proposal are: (1) To find out the occurrence and concentration of other EDCs in wastewater and surface water in the border area. We hypothesize that there will be varieties of unregulated EOCs found in wastewater influents and effluents. The concentration and occurrences of EDCs will depend on the source of wastewater. A newly developed solventless technique, called Stir Bar Sorptive Extraction coupled with Thermal Desorption and Gas Chromatography/Mass Spectroscopy will be employed for the analysis. A Geographical Information System (GIS) will be used for capturing, storing, analyzing, and displaying geographically referenced information. (2) To measure total estrogenic activity of various EDCs using bioassays. The assay used will be the transactivation assay or reporter gene assay. Briefly, MCF-7 breast cancer cells will be transfect with a reporter plasmid containing the estrogen receptor response element linked to luciferase. Luciferase activity will be measured to quantify the estrogenic activity of the wastewaters and assess the potential accumulative effects of the estrogenic chemicals on human health. (3) To assess how well we are protecting human health in the Paso del Norte area by the evaluating the quality of our treated water. The existence of EDCs in pre- and post-treated water in each treatment stage will be used to evaluate the effectiveness of EDC removal in current treatment process. In our area, recycling and reusing treated water is becoming principal water management option. To ensure the quality of our water is a necessary step to protect human health as well as aquatic life. The result will provide assessment on what small or large changes could be necessary to protect our water resources.